Shaking sieve device with transverse girders for the sieve plate



April 21, 1959 HElNZ-JOCHEM MAEDER 2,883,051

SHAKING SIEVE DEVICE WITH TRANSVERSE GIRDERS FOR THE SIEVE PLATE 4 Shets-Sheet 1 Filed Aug. 5, 1956 Fill). ll!

April 21, 1959 HElNZ-JOCHEM MAEDER 2,883,051

SHAKING SIEVE DEVICE WITH TRANSVERSE GIRDERS FOR THE SIEVE PLATE 4 Sheets-Sheet 2 Filed Aug. 3, 1956 INVENTOR He in a Ja /Sa M en Pr 5 H-a w p 1959 HElNZ-JOCHEM MAEDER 2,383,051

SHAKING SIEVE DEVICE WITH TRANSVERSE GIRDERS FOR THE SIEVE PLATE Filed Aug. 3, 1956 4 Sheets-Sheet s INVENTOR. n. 0 69* N A nl 21, 1959 HEINZ-JOCHEM MAEDER ,583,

SHAKING SIEVE DEVICE WITH TRANSVERSE GIRDERS FOR THE SIEVE PLATE 4 Sheets-Sheet 4 Filed Aug. 3, 1956 l Y W 12 I M SHAKTNG SIEVE DEVICE WITH TRANSVERSE omnnus FOR THE SKEVE PLATE Heinz-Joclrem Maeder, Kohl, Germany, assignor to Kliickner-Hurnboldt-Deutz Aktienge'sellschaft, Kohl- Deutz, Germany Applicafion August 3, 1955, Serial No. 601,866 Claims priority, application Germany August 6, 1955 6 Claims. (Cl. 209-269) The invention relates to a shaking sieve on which goods will be conveyed from one end of the sieve to the other while the sieve is partly submerged in a liquid such as water. With such sieves, if supported by transverse girders, there is the danger that owing to the resistance of the liquid to the moving submerged parts, liquid passing from underneath through the sieve forms, on the sieve surface above the girders, a kind of a dam which is at right angles to the direction in which the goods are conveyed and thus hampers the movement of the goods on the sieve.

It is an object of the invention to provide means Whereby such danger can be avoided.

The invention further aims to provide between each girder and the adjacent sieve surface, a substantially Wedgelike slot whereby liquid passing therethrough will be accelerated in a predetermined direction.

Another object of the invention contemplates to provide the transverse girders with a relatively narrow elongated cross-section symmetrically formed With respect to a longitudinal center line, wherein that line of symmetry includes a very small angle with the median direction of the sieve oscillations.

Further objects and details of the invention will be apparent from the description given hereinafter and the accompanying drawing illustrating several embodiments thereof by way of example.

In the drawing:

Fig. 1 is a longitudinal section of a sieve device according to the invention,

Fig. 2 is a section along line 22 in Fig. l, on a larger scale,

Fig. 3 is a cross-section along line 3-3 in Fig. 2,

Fig. 4 is a cross-section similar to Fig. 1 of a modification,

Fig. 5 is a partial cross-section along line S-5 of Fig. 4, on a larger scale,

Fig. 6 is a cross-section along line 66 of Fig. 5,

Fig. 7 is a cross-section of another modified part, and

Fig. 8 is a cross-section along line 88 in Fig. 7.

Referring now to the drawing, Figs. 1 to 3, a funnelshaped container 8 is enclosed by a reinforcing frame 5 welded thereto. The funnel is supported from the fundament 7 with the aid of resilient means, such as helical springs 6 arranged on the lower side of the frame and capable of taking up oscillating movements. Instead of the helical springs, rubber springs may be used. At its lower end, the funnel ends in a cylindrical portion 10 at which a valve (not shown)- may be attached. It is also possible to omit the valve and to provide on the fundament a draining bucket elevator which may be connected to the cylindrical piece 10 by means of a flexible tube. At the left-hand front wall 26, preferably an overflow 16 is provided with a weir 2.0, adjustable as to its height. The funnel is filled with a liquid, for instance water, the weir allowing an adjustment of the water level so that the sieve plate or bottom 1 of a sieve box 1 can be submerged more or less in the water. Spaced from the lefthand front wall 26, a partition 14 is arranged in the funnel so that its lower edge is at a distance from the funnel bottom. The partition includes with the front wall and the side Walls of the funnel, a space 27 which in its lower portion freely communicates with the remainder of the funnel space.

The sieve of the box 1 may have a mesh width of, for instance 3 mm. The box 1. is connected by guide elements 3, which may either be formed as endwise pivoted rods or as springs. They are so arranged that they extend at right angles to the median position of the direction of the oscillation of the masses, as it will be explained hereinafter. The sieve plate 1 forming the bottom of the box has a portion 17 which first descends very steeply and is then continued by a less steep portion of the sieve. The latter rises slightly with its portion 18, leading to the discharge 4.

At both side walls 22 of the funnel, bearings are provided, preferably on the lower side of the reinforcing frame. In these hearings, a crank shaft 13 is journalle'd on the outer shaft stubs on which a wedge belt pulley and a fly-wheel are, respectively, mounted. wheel is so dimensioned that the weight of the wedge belt pulley is balanced. It is also possible to compensate the weight of the motor 9 by making the fly-wheel correspondingly heavy. The median portion of the shaft is preferably cranked towards the side opposite to which the cranks of the shaft are directed, in such a manner that the masses of the shaft including the rotating portions of the connecting rods will be balanced. Owing to the fact that the crank radii will be only a few millimeters long, it is possible to use an eccentric shaft rather than a crank shaft. The shaft is enclosed by a transverse channel or tube 25 which is shown with a circular crosssection which, however, may have any other suitable form. The tube is welded to the side Walls 22 of the funnel, which are correspondingly perforated. In this manner, the shaft can be readily passed through the funnel space. The crank shaft forms two crank drives together with the connecting rods 12, which engage the sieve box by means of the links 19. The crank shaft is driven by an electric motor 9 through the wedge belt pulley and a wedge belt. The motor is secured to the lower side of the reinforcing frame. It may however, be arranged at any other suitable part of the funnel inasmuch as the distance of the motor from the crank shaft does not change during the operation. The inclination of the connecting rod 12, however, is preferably not freely selected but chosen according to the following explanation: If, on the one hand, ST is the center of gravity of the funnel including the parts secured thereto and also including the water, and if, on the other hand, SS

is the center of gravity of the sieve box with associated parts, then the connecting rods are suitably so arranged that their center line in the median position lies in a certain plane. This plane is at right angles to the plane of the drawing and passes through both the said centers of gravity. In that event, the geometric center line of the crank shaft must lie in the same plane. In this advantageous arrangement, the directions of oscillations of both masses, namely, that of the sieve box as working mass and that of the funnel with the Water as counter mass, will coincide and no free mass forces or mass moments will occur. The oscillations of both masses are oppositely directed and the amplitudes are inversely proportional to the masses. In order to improve the sieving and cleaning, sprinklers 2 are arranged above the sieve portion which projects from the water.

The ends 23 of the sieve plate 1' are fastened to transverse beams (not shown) of the sieve box. The plate bears on transverse girders 21 according to the in,

3 vention, which are spaced from each other and which are located at the bends of the sieve plate above and otherwise below the latter. In this manner, the sieve plate is spanned somewhat bow-like. As stated hereinbefore, the transverse girders according to the invention have a relatively narrow elongated cross-section which is preferably symmetrically formed with respect to a longitudinal center line, and the girders are so located that the lines of symmetry of their cross-sections include very small angles with the median direction of the sieve oscillations. According to a suitable embodiment of the invention and clearly shown in Figs. 2 and 3, each transverse girder 21 consists of a rubber body 32 provided with a steel core 33. This has the advantage that owing to the elasticity of the rubber body, the sieve plate will not lift from the transverse girders and that owing thereto, the wear of the sieve plate will be reduced. The sieve plate bears on such transverse girders 21. The girders extend between the side walls 22 of the sieve box 1 and are secured thereto by any suitable and conventional means. As stated above, the cross-section of each transverse girder is narrow and elongated and preferably streamed-lined. On the upper side of each girder two or more lug-like projections 24 are provided upon which the sieve plate 1' bears, as clearly shown in Figs. 2 and 3. The projections 24 are integral with the rubber body 32. Owing thereto, a gap 29 remains between each two lugs 24. According to the foregoing, the cross-section of the transverse girders is formed symmetrical with respect to a line of symmetry 30, and the girders are so secured to the side walls 22 that the line of symmetry 30 includes with the mean direction 12' of oscillation a very small angle 13 of about 7 to 15 degrees. The mean direction of oscillation coincides with the straight line which passes through the axes of the transverse rod 28 and the crank shaft 13 and which at a, as shown, has an inclination of about to 45 degrees with respect to the horizontal plane. Owing to the mentioned position of the transverse girders, a substantially wedge-shaped slot 31 is formed between the sieve plate 1' and each girder. The slots are narrower at their ends facing the discharge end of the sieve than at their opposite ends, and the narrow slot ends communicate with the gaps 29 between the projections 24 of the respective girders.

The manner of action of these transverse girders according to the invention is as follows:

During the downward movement of the sieve box, the water in the wedge-shaped slots 31 according to Fig. 3 will be accelerated in the direction of the arrow B because the slots act in the manner of jets. It is well known that the pressure of a liquid will decrease when the liquid passes through a jet, whereas the velocity will be increased. In consequence, there will be no pressure area in front of the transverse girder. The current which takes place during the downward stroke passes through the sieve plate at a small angle. In consequence, there is no danger of the water being deflected at right angles to the direction of the oscillation and the conveyance. The movement of the goods which have been charged on the sieve portion 17 to convey them upwards on the sieve portion 18 towards the discharge 4, will not be hampered.

Figs. 4 to 6 illustrate a modification providing for a stiffer and improved supporting of the sieve. For this purpose, each transverse girder is provided with several upwardly directed projections connected on top by a plane strip on which the sieve plate bears. A slot, similar to the slot 31 in Fig. 2, is formed between that strip and the transverse girder. In Fig. 4 the funnel 8 and its accessorial parts is of the same structure as that in Fig. 1. In sieve box 101, however, the shape of the sieve is slightly difierent from that of the sieve 1' but it comprises also a steeply inclined charging portion 117 and a much less inclined portion 118 leading upwards to the discharge end at 104. The mean direction of oscillation of the 4 sieve box, indicated by the line 112, passes through the centers of gravity ST and SS, through the pivot 128 of the connecting rod 12 and through the axis of the crank shaft 13.

As clearly shown in Fig. 4, the sieve plate 101 bears on several transverse girders, in general denoted by 40. Each transverse girder is formed as a guide body 36 of substantially fish-like shape on the top of which a striplike plate is arranged and secured thereto by a plurality of spaced connecting struts or supporting ribs 41. The plate-like strip 43 serves as bearing plate for the sieve 101. In the illustrated embodiment, the cross-section of the girder is lozenge-shaped and has a line of symmetry 130.

In an advantageous structure according to the invention, the girder body is hollow and welded together of sheet metal. Between the upper sheet metal strip 39 of the girder body, the strip 43 or the sieve plate and each two adjacent struts 41, a wedge-like slot is formed similar to and for the same purpose as slot 31 in Fig. 2. By means of the struts 41, the strip 43 is well stilfened, whereby a rigid support for the sieve plate 101' is obtained, and the water can freely flow through the wedgeshaped slots 45 during the oscillations of the sieve box. It will be noted that with reference to the angle between the lines 112 and the same applies as has been stated with respect to the angle 6 in Fig. 1.

If it is desired, in view of very difficult conditions to obtain a stiffer bearing for the sieve plate, the strip 43 may be provided at its front edge with a beading in order to stiffen the structure.

A still better stiifening, obtained by a very simple construction, consists as shown in Figs. 7 and 8, in that a steel L-beam 50 is used, the one leg 52 of which takes the place of the plate strip 43 in Figs. 5 and 6. The other downwardly directed leg is provided with several recesses 35 in such a manner that a beading 44 as well as further connecting struts 46 are created. At right angles to these struts 46, the supporting ribs 124 are welded which lie in the plane of the drawing in Fig. 8 and which have an approximately trapezoidal shape owing to the inclined position of the guiding girder body 36. During the operation, the Water flows between these ribs 124 and through the recesses 35 and either passes in an oblique direction through the sieve 101 or continues to flow along underneath the sieve surface.

Instead of the L-beam, other profiled beams may be used.

It will be apparent to those skilled in the art that modifications and alterations of the structure shown and described may be made without departure from the essence and spirit of the invention which for that reason shall not be limited but by the scope of the appended claims.

I claim:

1. A device of the character described comprising a container including means for maintaining a predetermined liquid level therein, a sieve box at least partly within said container and including side walls and an apertured bottom constituting a substantially troughshaped sieve, said sieve having a charging end portion and a discharging end portion and extending partly underneath said liquid level, a drive engaging said sieve box for shakingly oscillating it in a predetermined median direction thereby causing goods charged on said sieve to be conveyed towards the discharge end thereof, a plurality of transverse girders spaced from one another and extending between the side walls of said box underneath said sieve, each of said girders having a substantially narrow cross-section symmetrical with respect to .a line extending length-wise through said cross-section, said girders being so arranged that said lines of symmetry extend at very small angles with respect to the direction of the oscillations so as to form substantially wedgeshaped slots above said girders, respectively, to permit liquid to pass therethrough, said slots being narrower at their ends facing said discharge end portion of said sieve than at their opposite ends, a plurality of upwardly extending projections of each girder dividing the slot thereabove into a plurality of part slots and supporting said sieve, and further comprising in combination with each girder a. plate-like strip to which the upper ends of said projections are secured, said sieve bearing on said strips and said slots being formed between said strips and the associated girders.

2. A device of the character described comprising a container including means for maintaining a predetermined liquid level therein, a sieve box at least partly within said container and including side walls and an apertured bottom constituting a substantially troughshaped sieve, said sieve having a charging end portion and a discharging end portion and extending partly underneath said liquid level, a drive engaging said sieve box for shakingly oscillating it in a predetermined me dian direction thereby causing goods charged on said sieve to be conveyed towards the discharge end thereof, a plurality of transverse girders spaced from one another and extending between the side walls of said box underneath said sieve, each of said girders having a substantially narrow cross-section symmetrical with respect to a line extending length-wise through said crosssection, said girders being so arranged that said lines of symmetry extend at very small angles with respect to the direction of the oscillations so as to form substantially wedge-shaped slots above said girders, respectively, to permit liquid to pass therethrough, said slots being narrower at their ends facing said discharge end portion of said sieve than at their opposite ends, a plurality of upwardly extending projections of each girder dividing the slot thereabove into a plurality of part slots and supporting said sieve, and further comprising in combination with each girder a plate-like strip to which the upper ends of said projections are secured, each strip including a beading at its edge facing said discharge end portion, said sieve bearing on said strips and said slots being formed between said strips and the associated girders.

3. A device of the character described comprising a container including means for maintaining a predetermined liquid level therein, a sieve box at least partly within said container and including side walls and an apertured bottom constituting a substantially troughshaped sieve, said sieve having a charging end portion and a discharging end portion and extending partly underneath said liquid level, a drive engaging said sieve box for shakingly oscillating it in a predetermined medi-an direction thereby causing goods charged on said sieve to be conveyed towards the discharge end thereof, a plurality of transverse girders spaced from one another and extending between the side walls of said box underneath said sieve, each of said girders having a substantially narrow cross-section symmetrical with respect to a line extending length-wise through said cross-sec tion, said girders being so arranged that said lines of sym metry extend at very small angles with respect to the direction of the oscillations so as to form substantially wedge-shaped slots above said girders, respectively, to permit liquid to pass therethrough, said slots being narrower at their ends facing said discharge end portion of said sieve than at their opposite ends, a plurality of upwardly extending projections of each girder dividing the 6 slot thereabove into a plurality of part slots and supporting said sieve, and further comprising in combination with each girder an L-bearn being secured with both its legs to said projections which are rib-like arranged, said sieve bearing on the upper legs of said beams, and the downwardly extending legs of said L-beams being recessed between each two adjacent rib-like projections to form passages communicating with said narrower ends of said slots.

4. A device of the character described comprising a container including means for maintaining a predetermined liquid level therein, a sieve box at least partly within said container and including side walls and an apertured bottom constituting a substantially troughshaped sieve, said sieve having a charging end portion and a discharging end portion and extending partly underneath said liquid level, a drive engaging said sieve box for shakingly oscillating it in a predetermined rne dian direction thereby causing goods charged on said sieve to be conveyed towards the discharge end thereof, a plurality of transverse girders spaced from one another and extending between the side walls of said box underneath said sieve, each of said girders having a substantially narrow cross-section symmetrical with respect to a line extending length-wise through said cross-section, said girders being so arranged that said lines of symmetry extend at very small angles with respect to the direction of the oscillations so as to form substantially wedgeshaped slots above said girders, respectively, to permit liquid to pass therethrough, said slots being narrower at their ends facing said discharge end portion of said sieve than at their opposite ends, a plurality of upwardly extending projections of each girder dividing the slot thereabove into .a plurality of part slots and supporting said sieve, and further comprising in combination with each girder an L-beam being secured with both its legs to said projections which are rib-like arranged, said sieve bearing on the upper legs of said beams, and the downwardly extending legs of said L-beams being recessed between each two adjacent rib-like projections to form passages communicating with said narrower ends of said slots, said recesses being spaced a short distance from the adjacent ribs and from said upper leg whereby the latter is provided with a beading above said recesses, and additional supports between each girder and its associated beam are formed by portions of the other leg between each two adjacent recesses.

5. A device as in claim 1 wherein the cross-sections of the girders are lozenge-shaped.

6. A device as in claim 1 wherein said girders are hollow and the walls of the girders are formed by and composed of sheet metal.

References Cited in the file of this patent UNITED STATES PATENTS 1,160,502 Frantz et a1 Nov. 16, 1915 1,237,237 Bookwalter Aug. 14, 1917 1,312,324 Hawkins Aug. 5, 1919 1,313,984 Fanning Aug. 26, 1919 1,361,772 Quellette Dec. 7, 1920 2,089,548 Frantz et al Aug. 10, 1937 2,115,110 Keil Apr. 26, 1938 2,293,978 Jonsson Aug. 25, 1942 

